1. Technical Field
The present disclosure relates to a light source driving device, and more particularly to a light source driving device having a high-frequency light dimming function.
2. Related Art
Since light emitting diodes (LEDs) are small, power saving and durable and since the manufacturing technique of the LED becomes mature, products using the LEDs as a light source has gained in popularity.
Generally speaking, the LEDs may be driven by driving circuits such as, a chip with a model of MP-2370 or MP-2483, for generating light. Under a fixed current mode, the driving circuit performs on-off control with a switch frequency of approximately 1.6 MHz, so as to give power to the LED, and keep the brightness of the light generated by the LED stable.
However, in a light dimming mode, the driving circuit uses a light dimming signal of a square wave having a frequency of approximately 100 Hz-2 kHz. Next, the driving circuit performs on-off control on the power source required by the LED according to the duty cycle of the square wave, so as to perform a light dimming function on the LED. However, in the light dimming mode, since the original switch frequency of 1.6 MHz in the driving circuit is reduced to 100 Hz-2 KHz, the flickering the LED may be sampled by an image sensor (for example, 1/120 second and 1/240 second under short exposure), so that pictures captured by the image sensor may also flicker.